Two Irishmen are a drift in a life raft, when a corroded old brass bottle drifts by. Paddy grabs the bottle and shakes it - at which point the top falls out - and - out pops a Genie.
The genie looks at the two desperate men and says that he will grant them only one wish.
At this Paddy blurts out, "Well, okay, turn the ocean into Guinness*!"
And poof - the Genie complies. The ocean has been turned into a fine stout brew.
Sean, scratches his head, looks a Paddy with contempt and says,
"Paddy, you idiot!!! Now we're gonna have to pee in the boat!!!"
Guinness* - a kind of alcoholic drink